The invention relates to a device for closing a pipe branch, especially for closing either orifice of a Y-shaped distributor connection.
In the extraction of bulk material from silos, it is often necessary to convey the extracted bulk material alternatively to two or more locations separated in space. Conversely, it is possible to convey bulk material from two or more different silos to a common extraction point. At the same time, it is necessary to ensure that at no time gas or solids, and in special cases also liquid, are able to pass from the line carrying bulk material at that particular moment into the closed line. That is to say the line segments must be absolutely leakproof relative to one another.
The feed connection directed downwards or upwards in a Y-shaped manner can be closed in various ways. For example, slides, flaps, a common pivoting flap, ball valves, rotary plugs or the like can be mounted in both connections. The disadvantage of these devices is that there can form above the closing device dead zones in which bulk material accumulates under certain circumstances, this deposited material being released again when the closing device is opened. Furthermore, the connecting orifices can be sealed off only ineffectually.
German Utility Model 1,977,787 and German Patent Specification No. 277,519 disclose distributor devices, in which the Y-shaped distributor connections can be closed by means of a common rotary plug designed as a rotary cylinder of oblique cylinder section, the center axis of the rotary plug being aligned with the pipe axis of the inflow connection. With the known devices, although it is possible in a simple way to change over the respective junction connections to be put in communication, nevertheless devices of this type, in terms of their sealing, are sensitive to bulk materials since the sealing surfaces come to rest directly in the bulk-material stream. Insofar as the inflow connection is given the same inside throughflow diameter as the two junction connections, there are problems in the matching of the rotary plug, since the connecting orifices of the junction connections cannot be closed completely by the cylindrical surface of the rotary plug. Consequently, in the known devices, the junction connections are always designed with a smaller inside diameter. An alternative solution to this is shown in German Patent Specification 277,519. Here, the closing device is not designed as a simple rotary plug having an oblique cylinder section, but is made substantially more complicated.